The present invention relates to fluid product dispenser comprising a tank of fluid product and vibrating membrane that serves as a dispenser part. In general, the vibrating membrane is pierced with one or more dispenser holes through which the fluid product is dispensed under the effect of the vibration of the membrane. Means of vibration are generally provided in order to vibrate this pierced membrane: a piezoelectric part can constitute good vibration means to vibrate the membrane.
The present invention relates more particularly to the cosmetics, perfume or pharmaceuticals sectors. The dispenser is therefore small enough to enable the user to take hold of it with a single hand. The user should also be able to actuate the dispenser with a single hand by pressing an actuator button intended to actuate the vibration means of the membrane.
In a standard pump that operates using suction and back-flow techniques, the pressure inside the tank does not act directly on the pump operation. A standard pump can operate with a tank that is pressurized or under vacuum, provided that excessive values are not reached. This is not the case with a pierced vibrating membrane that has neither an inlet nor an outlet valve. Consequently, the fluid product must be supplied to the vibrating membrane under pressure that is more or less equal to that of the atmosphere. A very slight vacuum or overpressure is, however, acceptable. If the tank is under pressure fluid product may leak through the holes in the pierced membrane, which would result in unacceptable seepage. On the other hand, a vacuum inside the tank would cause air to penetrate the dispenser through the holes of the pierced membrane. The spray would also be very poor quality.
In European Patents 0 615 470 and 0 696 234 fluid product dispensers are described that comprise a tank and a pierced membrane that vibrates by means of a piezoelectric part. Fluid supply means are provided that connect the tank to the membrane in order to supply the pierced membrane from the tank. As the pierced membrane is located above the tank under normal operating conditions it is necessary for the fluid to ascend against the force of gravity. In order for this to be possible, the supply means are capillary conduits in which the fluid products ascend naturally until they reach the pierced membrane.
However, it is not always easy to control the supply due to the fact that it uses capillarity.
Consequently, the aim of the present invention is to overcome the above-mentioned drawbacks of the prior art due to capillarity by using another type of fluid-product supply from the tank to the vibrating membrane.
In order to achieve this, under normal operating conditions the tank is located above the pierced membrane such that the fluid product is supplied to the membrane from the tank using the force of gravity. The supply to the membrane therefore no longer depends on specific physical characteristics, i.e. capillarity, that cause the product to be dispensed at random. Gravity ensures that the membrane is directly and reliably supplied with fluid product under pressure that is more or less equal to that of the atmosphere. The term xe2x80x9cunder normal operating conditionsxe2x80x9d implies the period during which the button is actuated to activate the means of vibration. In other words, in the invention the tank is located above the membrane when the actuator button is depressed.
Advantageously, the dispenser includes a bottom that is intended to come into contact in the rest position with a surface that is more or less horizontal, the tank then being located above the vibrating membrane.
According to another advantageous characteristic, the membrane is connected to the tank by a passage provided with an inlet valve capable of opening and cutting off the passage selectively.
The vibration means and inlet valve are preferably electrically controlled. The inlet valve enables the membrane to be isolated from the tank such that said membrane is not subjected to any pressure. Any risk of the fluid product leaking or seeping through the holes of the pierced membrane is therefore avoided. Advantageously, the inlet valve only opens in periods during which the dispenser is actuated, i.e. when the actuator button is depressed. For example, the actuator button can activate the vibration means and open the inlet valve simultaneously. The pierced membrane is only therefore supplied with fluid product in the periods during which the dispenser is actuated.
According to another characteristic of the invention, the tank includes an upper section provided with an venting passage. Advantageously, the venting passage comprises a part made of porous material. The venting passage ensures that the pressure of the fluid product inside the tank is always more or less the same as atmospheric pressure. Furthermore, the passage is positioned at the top of the dispenser to prevent the fluid product from leaking through said passage.
According to another characteristic, the actuator button is located in the upper section of the tank and the venting passage is formed around said actuator button. The venting passage is also formed between the actuator button and the upper section of the tank. Advantageously, the actuator button masks the part made of a porous material. The actuator button is therefore used to both create and mask the venting passage.